1. Field of the Invention
This invention relates to a one-piece plastic closure to be fastened on a container neck, with a fastener on the container neck for the interlocking and/or frictional connection of the plastic closure with the container neck, wherein the plastic closure has a lower element and a cap pivotably connected by at least one film hinge.
2. Description of Prior Art
Increasingly greater demands are made by manufacturers for security of packaging, in particular in connection with packaging of food and cosmetics. With most current closures, depending on the type of the closure, either the connection between the closure and the container is secured appropriately, or guarantee elements are provided, which are intended to indicate intactness. While the first mentioned variation has screw closures in particular, the second mentioned embodiment mainly has a flip top. With most of the last mentioned variations, these are so-called snap hinge closures. There is a conventional plastic flip-top closure with a guarantee element described in PCT International Application WO 94/03371, wherein a guarantee element indicates whether the cap has been opened with respect to the lower element of the closure, and also indicates if, following the original closed state, the closure has been removed from the container. This solution does not use a guarantee strip, but a tear seal provided in the cap surface, which extends through the upper cover surface of the lower element and is in interlocking and frictionally-connected engagement with the fastening means on the container neck by a detent shoulder. It has been shown that this extremely elegant solution places extremely high demands on the production technology, and in the course of assembly often leads to defects, particularly of the seal. A further problem is that the destruction of the seal apparently is less obvious to the public than a customary guarantee strip when it has been torn off.
The guarantee strips of flip hinge closures are arranged on the lower element of the closure, and appropriate protrusions are arranged on the cap, which allow an interlocking connection between the cap and the guarantee strip, and therefore indirectly with the lower element. A one-piece plastic closure is known from PCT International Application WO 93/00271.